On Thursday, the airline introduced a new tiered pricing structure that raised the price of alcoholic drinks between $1 and $2. Miller Lite, Dos Equis and wine will cost $6, while liquor and premium beer (like Fat Tire, Lagunitas and Leinenkugel's Summer Shandy) will cost $7, according to an airline spokesperson.

Southwest previously offered all beer, wine and spirits for $5.

Soda, coffee, water, juice and other non-alcoholic drinks remain complementary. The airline will also continue to offer a round of free drinks on Valentine's Day, St. Patrick's Day, Halloween and June 18, Southwest's birthday.

A Southwest spokeswoman told ABC via email that the price hike is the first since 2009, adding that the airline's famous free drink coupons will remain valid for all alcoholic drinks regardless of price.